Key Notes
- The KOSPI closed at 6,941.39, down 0.89%, as Samsung fell 1.45% and foreign investors sold a net ₩1.75 trillion of Korean shares.
- Goldman Sachs warns that Samsung’s October 8 earnings, semiconductor ETF rebalancing and monthly options expiry could increase near-term share-price volatility.
- Samsung’s ₩15 trillion buyback may finish ahead of its November 21 deadline, reducing recurring demand while earnings remain the main fundamental test.
South Korea’s KOSPI closed below 7,000 on October 6 as selling in major chipmakers weighed on the market ahead of a busy trading calendar for Samsung Electronics Co. Ltd. (KRX: 005930).
The benchmark closed at 6,941.39, down 62.35 points, or 0.89%, according to Yonhap. Samsung finished at ₩272,000, down 1.45%, while SK hynix Inc. (KRX: 000660) fell about 3.7% to ₩1,773,000, Aju Press reported.
Goldman Sachs Group Inc. (NYSE: GS) analyst Heather Oh warned of heightened volatility on Thursday, October 8, when Samsung’s preliminary earnings coincide with ETF rebalancing and options expiry, Investing.com reported, citing a client note.
Foreign Selling Keeps Pressure on Korean Stocks
Foreign investors sold a net ₩1.75 trillion, or about $1.3 billion, of Korean shares on Tuesday, according to Yonhap. The KOSPI opened higher before reversing course, with technology losses pulling the index below the round-number threshold.
The decline was not uniform across the market. The technology-heavy KOSDAQ rose about 3%, Aju Press reported, as chip-equipment, battery and biotech shares gained. That contrast points to differences in positioning within Korean equities rather than a selloff in every technology business.
For Samsung shareholders, the immediate question is how much of the pressure reflects expectations for profits and how much reflects investors adjusting their portfolios. The events approaching on Thursday can affect both.
Earnings Arrive Alongside ETF Rebalancing
Goldman estimates Samsung’s third-quarter operating profit at ₩106 trillion, compared with consensus of ₩105.5 trillion, according to Investing.com. The bank reduced its earlier ₩112 trillion forecast, mainly because of a stronger won.
Those figures remain analyst estimates ahead of the preliminary release. Currency movements can change the won value of overseas sales, making exchange-rate assumptions important even when demand for memory chips remains strong.
Samsung’s last completed quarter provides the financial backdrop. Its official quarterly results showed record second-quarter revenue of ₩171.5 trillion and operating profit of ₩89.5 trillion. The semiconductor division contributed ₩89.2 trillion in operating profit, supported by AI-related server demand and higher memory prices.
The company also expected robust server demand in the second half, while noting some moderation in mobile and PC demand. MarketSpeaker’s earlier Samsung earnings coverage examined that growing importance of the chip business.
Seven semiconductor ETFs holding roughly ₩19 trillion in assets are due to rebalance on October 8, Goldman said in the reported note. Portfolio weight limits could generate Samsung selling.
Such transactions follow fund rules rather than a fresh judgment about earnings. A holding that exceeds its permitted weight can require trimming even when the company’s outlook is healthy. The resulting orders may add pressure around a scheduled rebalance, although their net effect depends on demand from other investors.
Options Expiry Adds Another Moving Part
The Korea Exchange’s options calendar sets the last trading day for monthly KOSPI 200 options on the second Thursday of the contract month. In October 2026, that falls on October 8.
Expiring contracts can prompt traders to close, roll or adjust positions, along with the hedges used to manage them. When an earnings release arrives on the same day, investors must respond to new company information while existing derivatives positions reach their deadline.
The exchange specifies cash settlement for these index options. Expiry therefore does not automatically require delivery or sale of Samsung shares. Any additional equity-market pressure comes through positioning and hedging decisions, and its direction is not predetermined.
Buyback Support Could Fade Before the Formal Deadline
Goldman also expects Samsung’s ₩15 trillion repurchase program to finish this week, removing a recurring buyer.
Samsung’s official buyback filing gives an expected purchase window of August 24 through November 21. An earlier completion is possible if the authorized spending is used, but October 8 is not the formal end date in that disclosure.
The filing says the open-market purchases are intended to provide treasury shares for employee and executive stock-based compensation. That purpose matters: this program should not be described as a commitment to cancel every repurchased share.
If buying ends before the deadline, Samsung would lose one source of daily demand just as other investors adjust holdings. Actual completion remains a separate company disclosure to watch.
The broader backdrop remains difficult. MarketSpeaker’s Treasury coverage tracked Monday’s multidecade yield highs, which raise the returns available from bonds and the discount rates investors apply to future corporate profits.
Thursday’s preliminary earnings will offer the next test of Samsung’s profit momentum. The market reaction will also reflect fund flows and the remaining buyback capacity, making the release-day share price an imperfect measure of the company’s operating performance.
